[SimplifyCFG] Bail out on vector GEPs in `passingValueIsAlwaysUndefined` (#142526)

Closes https://github.com/llvm/llvm-project/issues/142522.

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 245d0c4..e221022 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -8108,6 +8108,7 @@ bool SimplifyCFGOpt::simplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) {
 
 /// Check if passing a value to an instruction will cause undefined behavior.
 static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I, bool PtrValueMayBeModified) {
+  assert(V->getType() == I->getType() && "Mismatched types");
   Constant *C = dyn_cast<Constant>(V);
   if (!C)
     return false;
@@ -8165,6 +8166,10 @@ static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I, bool PtrValu
     // Look through GEPs. A load from a GEP derived from NULL is still undefined
     if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User))
       if (GEP->getPointerOperand() == I) {
+        // The type of GEP may differ from the type of base pointer.
+        // Bail out on vector GEPs, as they are not handled by other checks.
+        if (GEP->getType()->isVectorTy())
+          return false;
         // The current base address is null, there are four cases to consider:
         // getelementptr (TY, null, 0)                 -> null
         // getelementptr (TY, null, not zero)          -> may be modified